Circular Saw Cutting Machine

A circular saw cutting machine ( 1) includes a machine main body (10)， an articulated robot (60)， and a cutter stocker (70). A circular saw (5) is secured and interposed by a cutter clamp cylinder (CYL21) between a front end face (32) of the main spindle (21) and a cutter presser piece (50) with pins (33， 51) inserted in pin insertion holes (5b). When removing the circular saw (5)， a hydraulic is switched over to cause the cutter clamp cylinder (CYL21) to perform unclamping so that the cutter presser piece (50) can be pulled out of the main spindle (21). When the articulated robot (60) performs cutter change， a main spindle motor (M10) and a brake (25) are controlled based on the rotation angle detected by a spindle stop position sensor (SE10) to stop the main spindle (21) in a predetermined home angle condition.